Introduction: Actinomyces species play a major role in the development of oral biofilms and disorders associated with dental plaque. The purpose of this study was to look into their interactions, prevalence, and ability to form biofilms in dental plaque. Methodology: Dental plaque samples from 78 participants in a six-month cross-sectional research at KCD Peshawar were examined for Actinomyces species. The microtiter plate test was used to measure the production of biofilms, and statistical analyses were performed to investigate the relationships between Actinomyces presence, plaque severity, and biofilm formation capacity. Results: A total of 79.5% of samples contained Actinomyces species, with Actinomyces naeslundii being the most common (72.6%). Actinomyces was found to be significantly correlated with the severity of the plaque (χ² = 8.92, p = 0.012). In comparison to mild/moderate plaque (mean OD570 = 0.52, t(60) = 2.78, p = 0.007), isolates from severe plaque (mean OD570 = 0.61) formed more biofilms. Increased biofilm biomass was obtained through co-cultivation with Streptococcus mutans, particularly in combinations involving A. israelii and S. mutans. Conclusion: Actinomyces species are important in the development and severity of dental plaque, with more severe cases being associated with higher biofilm-forming capacity. Their relationships to Streptococcus mutans increase the pathogenicity of biofilms. Actinomyces targeting may be able to reduce tooth plaque-related illnesses. Larger populations and biological reasons for successful interventions should be investigated in future studies.